"Baby"
(most spinners bestow names on their spinning wheels) is a
portable spinning wheel made from one of Lee Valley's tea-cart
wheels*. The rubber tire on the wheel as purchased rolls off
quite easily, leaving a nice groove for the drive band. There
is not enough mass in the wheel for this application, so I
added brass weights around the circumference to give it a
bit more inertia. The tension adjustment on the drive band,
the horizontal adjustment of the "mother-of-all"
and the threaded shaft, which holds the spinning wheel open
for use or closed for transportation, are all fixed with knobs
from Lee Valley. There is even a buried rare-earth magnet
to hold the ball-bearing race from the shaft of the flyer
while the bobbin is being changed. (The orifice end of the
flyer is also fitted with a ball bearing. This is firmly attached
and is not at risk of getting lost as the shaft bearing did,
which was the stimulus to add the magnet.) The driving wheel
was also retrofitted with a shaft running on ball bearings
mounted in the frame of the spinning wheel, as the shaft supplied
is excessively sloppy in the hub of the wheel.

Spinning wheel folded for transportation.

The design of this spinning wheel presented a bit of a challenge.
The rocker bar provides a dual-treadle arrangement. This is
connected to the driving wheel by the "footman" (there is
a whole vocabulary associated with spinning equipment). This
had to be precisely the right length to permit the wheel to
fold just above the rocker bar so that the T-shaped base and
treadles fold flat against the wheel for transport or compact
storage. I must confess that I was surprised (and gratified!)
at how well my elaborate three-dimensional geometric calculations
turned out.